Harnessing the Gut Microbiome Separating the Hype from the Evidence

1. Harnessing the Gut Microbiome Separating the Hype from the Evidence Lee Jones CEO, Rebiotix Sept 2015

2. Pioneer in Microbiota Restoration Therapy • Privately held clinical stage company • Founded in 2011 to treat debilitating diseases by harnessing the power of the human gut microbiome • Developing new class of biologic drugs based on live human-derived microbes • First company to take this new class of drugs through the FDA

4. Good Hype: Fecal Transplant Cures All

5. Bad Hype: FT Causes Obesity • Weight Gain After Fecal Transplantation* • Pre FMT • Recipient weight: 133 lbs. • Donor weight: 140 lbs. • Post FMT (16 mos./36 mos.) • Recipient weight: 170 lbs./177 lbs. • Donor weight: 170 lbs. If both the recipient and the donor gained weight, does that mean being a donor makes you gain weight ???????? *Brief Report, OFID, 1 Alang et al

6. What is Reality? • Lots of promise – good and bad • Mostly anecdotal efficacy data • Overall lack of rigorous safety data • Both short and long term

7. Hype Creates False Hope

8. Commercial Perspective What we believed: • MRT had great promise • Fecal transplants seemed to work for recurrent Clostridium difficile infection (rCDI) • A logistics problem • Adoption slow due to manufacturing process • FDA approval a must for wide access and safety Targeted Product to Be: • Easy to use • Patient friendly • Fit into current medical practice • Safe and effective

9. Market Entry: Clostridium difficile • Debilitating infectious gastrointestinal disease • >29,000 US deaths annually* • Low risk bet in the microbiome space • Fecal transplant - historically proven treatment • Unmet medical need • There is no currently approved treatment for patients with 2 or more recurrences • Growing population* *Burden of Clostridium difficile Infection in the United States, NEJM 2015:372:825-34

10. Commercialization Strategy: rCDI • Strategy: Comprehensive clinical trial plan to produce medical based scientific evidence (no hype) • Product Objective:Standardized, quality controlled, FDA approved product • Lead Product: RBX2660 • Full spectrum microbial composition • Cryopreserved • Enhanced donor screening • Simple off-the-shelf enema delivery system • No anesthesia or bowel prep* *Currently only product under IND investigation in US without bowel prep

11. Clinical Trial Strategy: Recurrent C diff

12. 2012 Beliefs: The Good, The Bad, and The Ugly Nearly 100% cure with one treatment Wouldn’t work if diarrhea wasn’t controlled by antibiotics before transplant Need colonoscopy bowel prep regardless of method of delivery Donor key to patient success If failure with one donor; second treatment needed different donor Best donors were related to the patient 100% safe - no adverse events

13. PUNCH™CD: Study Design • Safety – primary concern of FDA • Restricted inclusion criteria parameters • at least two recurrences of CDI after a primary episode • and have completed at least two rounds of standard-of-care oral antibiotic therapy OR • have had at least two episodes of severe CDI resulting in hospitalization prior to enrollment

14. PUNCH™CD: Baseline Characteristics • Failed antibiotics • Metronidazole, Vancomycin, Fidaxomicin; including Vancomycin and Fidaxomicin tapers • Patients were at high risk for recurrence and generally very ill at enrollment • Patients typically had one or more comorbidities

15. PUNCH™ CD Open Label Safety Trial* *not an intent to treat study

16. PUNCH™ CD: Safety Assessment Methods • AEs solicited during 6-month follow-up after each dose of RBX2660 • First 7 days: study diary documenting 11 pre-specified types of AEs • Patients asked about AEs during all encounters: • Office visits: 7,30 and 60 days • Calls: weekly through 8 weeks; at 3 and 6 months • Investigator and study medical monitor evaluated AEs for: • Seriousness • Severity • Causality/relatedness to: • RBX2660 • Enema procedure • CDI • Pre-existing condition

17. PUNCH™ CD: AEs • GI disorders were most commonly reported • Of the most common GI AEs - diarrhea, flatulence, abdominal pain, and constipation – all cases were self-limiting

18. PUNCH™ CD: SAEs All events were adjudicated by an independent medical monitor and were determined to be unrelated to the product or the procedure Serious Adverse Events Through 60-Day Follow-up

19. PUNCH™ CD: Efficacy • 87.1% represents absence of CDI at 8 weeks • No additional occurrences in successful patients out to 6 months with/without antibiotic treatment for other indications

20. PUNCH™ CD: Efficacy • First enema of RBX2660 was administered after a 10-14 day course of antibiotics • Second enema of RBX2660 was administered without antibiotic pre-treatment

21. PUNCH™ CD: Observations • Patients had long standing disease and multiple co-morbidities • There were nuances to their treatment • One dose only efficacy appeared to increase as sites gained experience with MRT for RCDI

22. Does the Donor Effect Patient Outcome? Methods • Patients who required 2 doses could receive RBX2660 manufactured from the same or different donors. • Same pair of donors could also be used in a different order. NO! Success was not impacted by the donor or dose order Results • 34 patients (mean age 68.8 years, 67.6% female) received at least 1 dose of RBX2660. • 19 patients received 1 dose and 15 patients received 2 doses.

23. Additional Proof-of Concept • Secondary analysis of Vancomycin Resistant Enterococcus (VRE) clearance in infected patients • 8/10 patients testing positive for VRE became negative • Additional study needed to further assess the relationship between VRE and CDI clearance

24. PUNCH™ CD: Conclusions • Rigorous, independent assessment of AEs • Overall satisfactory safety profile • No serious AEs attributed to RBX2660 or its administration • GI-related AEs common within 7 days of first dose • Declined over time • Less common with second dose • Overall efficacy 87.1% • Efficacy of second dose with no antibiotic pretreatment higher than first dose with antibiotic pretreatment

25. 2012 Beliefs: The Good, The Bad, and The Ugly Nearly 100% cure with one treatment Wouldn’t work if diarrhea wasn’t controlled by antibiotics before transplant Need colonoscopy bowel prep regardless of method of delivery Donor key to patient success If failure with one donor; second treatment needed different donor Best donors were related to the patient 100% safe - no adverse events

26. 2015 Evidence:The Good, No Bad, No Ugly • Cure rate was high - but not 100% with one dose • Some patients needed more than one treatment; time related “healing” or regeneration of the microbiome was evaluated by longitudinal 16s rRNA gene sequencing • Product worked in patients with active diarrhea • Bowel prep of any kind was not needed • Donor did not affect outcome • Non-related universal donors worked • Cure was durable • No additional occurrences in successful patients out to 6 months with/without antibiotic treatment for other indications • Clearance of other MDRO organisms promising future indication

27. PUNCH™ CD 2: Groundbreaking MRT Trial First ever multicenter, randomized, double-blind, placebo controlled IND study for microbiota based drug • Multicenter, prospective efficacy and safety study • Randomized • Double blind • Placebo controlled • 120 patients • Three treatment arms • 21 sites in US and Canada • Enrollment completed Sept 2015

28. PUNCH™ CD 3 Confirmatory Trial • Multicenter, prospective efficacy and safety study • Randomized • Controlled • Two treatment arms • Up to 40 US and Canadian sites

29. RBX2660 Regulatory Milestones Sep 2015 Aug 2015 • Phase 2B enrollment completed Dec 2014 Mar 2014 Nov 2013 May 2013

30. Human Gut Microbiome: Expanding Clinical Frontier 2011 2015 Infectious Disease Metabolic Disease Neuro Gut Microbiota Fecal transplant for recurrent Clostridiumdifficile (rCDI) Liver Disease Inflammatory Disease

31. Expanding the MRT Universe • Room temperature stable oral formula in development • Partnering with researchers to: • Investigate new indications • Investigate new formulations

32. Harnessing the Power of the Gut Microbiome • Pioneering new microbiota based drugs to solve urgent unmet medical needs • “Dehyping” the “hype” by conducting clinical trials that generate medical-based scientific evidence • Providing wide access to potentially life saving drugs through FDA approval process • Changing the therapeutic landscape

33. Thank you Additional information, contact: Lee Jones Ljones@Rebiotix.com 651-705-8772